How Long Does it Take to Benefit From a Hard Workout?

Recovery = benefit and good scheduling = good training

As an informed Running Times reader, you probably follow a well-designed training program that includes a mix of key types of workouts. (And if you don't, head over to Running Times Training as soon as you're done with this article.) V02 max intervals, tempo runs, basic speed reps and long runs are likely integral parts of your schedule.

The goal of each type of workout is to stress a particular physiological system and produce an adaptation that ultimately allows you to run faster. For example, and in admittedly simplified terms, V02 max intervals, such as kilometer repeats at 5K race pace, improve your heart's ability to deliver oxygen to muscles. Tempo runs increase your capacity to process and clear lactate. Short, fast repetitions enable you to run fast yet relaxed by decreasing overall energy expenditure and improving communication between working muscles and the brain. Long runs encourage capillary and mitochondria growth. Over time, these changes produce faster races.

While the physiology behind these adaptive processes is well understood, how quickly your body adapts after a hard workout isn't as well known by most runners. Once you learn that, you can more logically structure your training so that you're allowing the stress-and-recovery cycle to work its magic.

Let's say in the past two weeks you've done a long run, a tempo run, a track workout and some short, fast reps. When will you be fitter from this run of training?

According to Pete Pfitzinger, an exercise physiologist and two-time Olympic marathoner, the process is cumulative. "Positive training adaptations occur from repeated stimulus created by training stress," he says. "I think of the accumulated adaptations to training as a rolling sum of:

1. Stress which leads to fatigue (hard training done in the past five days);

2. Stress which is starting to lead to positive adaptations (hard training done about five to eight days ago);

3. Stress which has created a positive adaptation (hard training done about eight days to three weeks ago); and

4. Stress which is losing its effect (hard training done more than three weeks ago)."

The fitness you have today is a balance of these four categories. But what about the singular benefits from a particular workout, like that set of mile repeats you did last Wednesday?

That's difficult to pinpoint exactly, but, says Pfitzinger, they're typically realized in about eight to 10 days. Joe Rubio, a two-time U.S. Olympic trials marathon qualifier and head coach of the ASICS Aggies, says that "most athletes will see a benefit from an individual workout 10-14 days after it is completed."

Pfitzinger stresses that while eight to 10 days is the typical window for realizing recent gains, the rate of adaptations varies among individuals and depends on overall lifestyle, genetics and balancing training stress with adequate recovery. (See this article for tips on speeding your recovery so that you can do hard workouts more often and benefit rather than be torn down by them.)

EFFECTS OF VARIOUS TYPES OF WORKOUTS

While running-specific adaptations are unquestionably cumulative, each piece within the framework has its own recovery timeline, and it's important not to overlook this critical point when planning your training. The best time to perform a specific workout depends upon the time it takes from doing it to realizing its benefits on goal race day, coupled with the recovery profile of a workout. As mentioned above, the short answer regarding gains -- for all the types of workouts -- is about eight to 10 days. However, because of the variant stresses that different workouts place on the body, each must be considered separately. (See "Scheduling Your Schedule", below.) Knowing this information means knowing what workouts make the most sense shortly before an important race.

V02 max intervals tax the body the most and take the most recovery time. Pfitzinger believes that full recovery takes about eight to 10 days. "You would want to do your last hard V02 max workout eight to 10 days before a major race," he says. "During training or before a less important tune-up race, you do not need to be completely recovered from one hard workout before doing another, so you could do another V02 max session after five or more days." Rubio agrees and has his athletes perform a V02 max workout approximately every seven to 14 days, and never in the final week before a major race.

Type of Workout

Example

Time Until Next Similar One

Day Before

Day After

VO2 Max

5 x 1000m @ 5K race pace w/ 400m recovery jog

5 or more days

recovery run

recovery run

Threshold

4-mile tempo run @ half marathon race pace

4 or more days

recovery run or speed development

recovery run, speed development or easy long run

Speed Development

12 x 200m @ mile race pace w/ 200m recovery jog

2-3 days

recovery run, tempo run or easy long run

recovery run, long run or tempo run

Long Run

18 miles @ 1:00/mile slower than marathon race pace

4 or more days

recovery run or speed development

recovery run

Lactate threshold recovery is closer to about four days. According to Pfitzinger tempo runs are the easiest to recover from because they don't break down the body as much as long runs or V02 max intervals. "A runner could do a lactate threshold workout about every four days and be fully recovered for a less important race. For a major race I would recommend eight days or more after the last lactate threshold workout."

Speed repetitions, if done as longer intervals like repeat 400ms, can be as taxing as V02 max workouts. However, Pfitzinger points out that a workout such as extended strides of 150m or 200m require less recovery and could be done closer to a race, and can be completed several times per week during training.

Recovery time from a long run varies, but four days is generally the minimum amount of time necessary for complete recovery, although glycogen stores usually are replenished within about 48 hours.

HOW TO MAKE ADJUSTMENTS

Given that the length of recovery and stress inflicted varies depending upon the workout, your running schedule should be structured strategically to maximize improvement and adaptations and -- most important -- race performance.

For example, if you're aiming for a peak performance at a Saturday 5K, don't crank out 6 x 800m at V02 max pace on the Tuesday before, as you will still be in the "stress which leads to fatigue" phase of recovery on race day. As Rubio explains, "If the key race was a few days following this particular workout, the athlete wouldn't see the benefit from it until the end of the following week." In fact, the stress inflicted upon the body and recovery required may actually hinder performance in your goal race. Instead, do your last V02 max, threshold and long runs eight to 10 days prior to the peak race and do something like 4-6 x 150-300m as a final tune-up workout.

By doing this you minimize or negate residual fatigue in the final days leading up to the race and are rested enough to reap the benefits of the workouts performed in the critical window of eight to 14 days prior. Shorter, faster turnover reps keep your nervous system primed yet aren't taxing enough to create lingering fatigue on race day.

KRISTIN BARRY is a two-time Olympic marathon trials qualifier with a best of 2:40:38.